State of immune-secretory system of intestinal mucosa, bacterial contamination of the small intestine, peritoneal exudate, portal and systemic venous blood, ultrastructural changes in the liver (electron microscopy) were studied in 167 patients with general acute purulent peritonitis (APP) and clinical-laboratory symptoms of endotoxicosis. It is demonstrated that the main links of APP pathogenesis are disorders of small intestine barrier function, massive bacterial translocation from intestinal lumen to abdominal cavity and portal circulation, damage of reticuloendothelial hepatic barrier manifested as fulminant macrophagal hepatic failure, "bursting" of infectious-toxic agents into systemic circulation with resultant toxico-septic shock and visceral insufficiency. This approach permits to classify three clinical stages of APP and to propose differential surgical policy and detoxication treatment for these patients.